哈密两个月没来月经了有几种原因(哈密怀孕四十天了不想要怎么办) (今日更新中)

WELLINGTON, Aug. 8 (Xinhua) -- A New Zealand study has found that people who work at least 50 hours a week can be up to three times more at risk of alcohol problems than people who work fewer hours.The study, conducted by the University of Otago, used data that followed more than 1,000 people born in Christchurch in 1977 through to age 30.Study leader Dr Sheree Gibb said it aimed to examine whether working hours were related to alcohol problems in early adulthood.Data from more than 1,000 participants at ages 25 and 30 showed a significant association between longer working hours and alcohol- related problems.Longer working hours were associated with higher levels of alcohol problems including frequent alcohol use and alcohol abuse or dependence.People who worked 50 hours or more on average a week were 1.8 to 3.3 times more likely to have alcohol-related problems than those who were not working, and about 1.2 to 1.5 times more likely to have alcohol-related problems than those who worked 30 to 49 hours a week.The higher risk of alcohol abuse for those who worked longer hours was evident in both men and women, according to the study.Gibb said the finding could suggest a need for consideration of policies and programs targeting individuals who worked long hours, with the aim of reducing rates of alcohol-related problems.The article had been accepted for publication by the UK-based journal Addiction.

BEIJING, Aug. 3 (Xinhuanet) -- NASA Tuesday confirmed a 4-foot in diameter sphere debris as a fuel tank that was part of the space shuttle Columbia's electrical power system,according to U.S. news reports.NASA engineers identified the 4-foot piece of spherical debris as one of the18 tanks that held chilled oxygen and hydrogen used by the shuttle's electricity-generating fuel cells.This Aug. 1, 2011 handout photo provided by the Nacogdoches Police Department shows a 4-feet in diameter sphere found in Lake Nacogdoches, Texas on Monday, Aug. 1. Police say low water levels at the lake during the drought have led to recovery of a container-like object that could be from space shuttle Columbia. The shuttle broke apart and burned in February 2003, scattering remnants over East TexasPolice in the city of Nacogdoches, about 160 miles northeast of Houston, said Monday the low water levels of Lake Nacogdoches during the record drought revealed an unexpected object that could be from space shuttle Columbia. The shuttle broke apart and burned as it re-entered the atmosphere on February 1, 2003.The tank will be moved to the Kennedy Space Center, where the rest of the Columbia is stored. Approximately 40 percent of the spacecraft has been recovered.

LOS ANGELES, July 3 (Xinhua) -- Warming of the ocean's subsurface layers will melt underwater portions of the Greenland and Antarctic ice sheets faster than previously thought, increasing the sea level more than already projected, a new study suggests.The subsurface ocean layers surrounding the polar ice sheets will warm substantially as global warming progresses, according to the study led by researchers from the University of Arizona (UA).In addition to being exposed to warming air, underwater portions of the polar ice sheets and glaciers will be bathed in warming seawater, said the study appearing on the website of the American Association for the Advancement of Science (AAAS) on Sunday.The research, based on 19 state-of-the-art climate models, proposes a new mechanism by which global warming will accelerate the melting of the great ice sheets during this century and the next."To my knowledge, this study is the first to quantify and compare future ocean warming around the Greenland and the Antarctic ice sheets using an ensemble of models," said lead author Jianjun Yin, a UA assistant professor of geosciences.According to the study, the subsurface ocean along the Greenland coast could increase as much as 3.6 F (2 C) by 2100.Most previous research has focused on how increases in atmospheric temperatures would affect the ice sheets, he said."Ocean warming is very important compared to atmospheric warming because water has a much larger heat capacity than air," Yin said. "If you put an ice cube in a warm room, it will melt in several hours. But if you put an ice cube in a cup of warm water, it will disappear in just minutes."Given a mid-level increase in greenhouse gases, the researchers found the ocean layer about 650 to 1,650 feet (200 to 500 meters) below the surface would warm, on average, about 1.8 F (1 C) by 2100. Along the Greenland coast, that layer would warm twice as much, but along Antarctica would warm less, only 0.9 F (0.5 C)."No one has noticed this discrepancy before -- that the subsurface oceans surrounding Greenland and Antarctica warm very differently," Yin said.Part of the warming in the North comes from the Gulf Stream carrying warm subtropical waters north. By contrast, the Antarctic Circumpolar Current blocks some of the subtropical warmth from entering the Antarctic's coastal waters.Even so, the Antarctic ice sheet will be bathed in warming waters, according to the study.This paper adds to the evidence that sea level would rise by the end of this century by around one meter and a good deal more in succeeding centuries, the study noted.The study, "Different Magnitudes of Projected Subsurface Ocean Warming Around Greenland and Antarctica," is scheduled for the upcoming edition of Nature Geoscience later this month.

WASHINGTON, June 16 (Xinhua) -- Cells in the human body are constantly being exposed to stress from environmental chemicals or errors in routine cellular processes. While stress can cause damage, it can also provide the stimulus for undoing the damage. New research by a team of scientists at the University of Rochester has unveiled an important new mechanism that allows cells to recognize when they are under stress and prime the DNA repair machinery to respond to the threat of damage.Their findings will be published Friday in journal Science. Cells in the human body are constantly being exposed to stress from environmental chemicals or errors in routine cellular processes. While stress can cause damage, it can also provide the stimulus for undoing the damage.The scientists, led by biologists Vera Gorbunova and Andrei Seluanov, focused on the most dangerous type of DNA damage -- double strand breaks. Unrepaired, this type of damage can lead to premature aging and cancer. They studied how oxidative stress affects efficiency of DNA repair. Oxidative stress occurs when the body is unable to neutralize the highly-reactive molecules, which are typically produced during routine cellular activities.The research team found that human cells undergoing oxidative stress synthesized more of a protein called SIRT6. By increasing SIRT6 levels, cells were able to stimulate their ability to repair double strand breaks. When the cells were treated with a drug that inactivated SIRT6, DNA repair came to a halt, thus confirming the role of SIRT6 in DNA repair. Gorbunova notes that the SIRT6 protein is structurally related to another protein, SIR2, which has been shown to extend lifespan in multiple model organisms."SIRT6 also affects DNA repair when there is no oxidative stress," explains Gorbunova. "It's just that the effect is magnified when the cells are challenged with even small amounts of oxidative stress."SIRT6 allows the cells to be economical with their resources, priming the repair enzymes only when there is damage that needs to be repaired. Thus SIRT6 may be a master regulator that coordinates stress and DNA repair activities, according to Gorbunova.

WASHINGTON, Aug. 2 (Xinhua) -- Breastfeeding protects against childhood obesity, but less than 4 percent of U.S. hospitals provide the full range of support mothers need for breastfeeding, according to a report issued by the Centers for Disease Control and Prevention Tuesday.Improving rates of breastfeeding by providing better hospital support to mothers and babies is an important strategy to improve children's health, including a reduced risk of childhood obesity, the monthly Vital Signs report said."Hospitals play a vital role in supporting a mother to be able to breastfeed," it said."Those first few hours and days that a mom and her baby spend learning to breastfeed are critical. Hospitals need to better support breastfeeding, as this is one of the most important things a mother can do for her newborn. Breastfeeding helps babies grow up healthy and reduces health care costs," it added.The report found only 14 percent of hospitals have a written and model breastfeeding policy.It also found in nearly 80 percent of hospitals, healthy breastfeeding infants are given formula when it is not medically necessary, a practice that makes it much harder for mothers and babies to learn how to breastfeed and continue breastfeeding at home.Additionally, only one-third of hospitals practise rooming in, which helps mothers and babies learn to breastfeed by allowing frequent chances to breastfeed.Finally, the report found in nearly 75 percent of hospitals, mothers and babies don't get the support they need when they leave hospitals, including a follow-up visit, a phone call from hospital staff and referrals to lactation consultants, and other important support systems in their communities.

来源：资阳报